Improved rock-drill point



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Letters Paten'tNo. 93,684, dated August 17, 1869.

lMPROVED ROCK-DRILL PDINT.

The Schedule referred t in these Letters Patent and makingjprt of the same.

To all whom it 'may concern 4Be it known that l', CHARLTON H. DAVIS, Of' San Francisco, in the count-y of San Francisco, and State of California, have|` invented a new and improved Rock- Drill Point; and I- do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to v make and use the same, reference being had to theV accompanying drawin gs, forming part of this specification, in which- Figures l, 2, and 3, represent my improvements in drills.' Y

Similar letters of reference indicate corresponding parts.

The nature of my invention consists in the con-l struct-ion or formation of the point of a rook-drill, as hereinafter more fully described. p

A is the body or shaft of the drill, a greater portion 'of which is broken away at x, a short distance from tionately as the same are reduced, (the required strength n for the cutting-parts being preserved,) and that the cutting has the effect tobreak away the rock at the central part-s, or the parts corresponding to the recessesof the drills,-in such a manner as to be a great economy of time and labor in drilling.

, The notches or recesses b can be made of any suitable shape, contiguration, or size, so as to reduce the length of the cutting-edge c, to admit of the rock opposite the recesses or depressions being easily broken oft' from the solid rook at the bottom -of the hole by the action of the parts of the drill-points'not removed.

Having thus described my invention, I claim as new, and Vdesire to secure by Letters Patent- Rock-drill points, provided with one or more notches or recesses b, substantially as herein shown and described, and for the purpose set forth.

The above specifica-tion of my invention signed by me, this 15th day of June, 1869.

CHARLTON H. DAVIS:

Witnesses:

FRANK BLOCKLEY, ALEX. F. ROBERTS.A 

